Historic Bethlehem Museums & Sites (HBMS) partnered with Lehigh University’s Dr. Mariah Hoskins to use Ground Penetrating Radar (GPR) to explore the nearby Colonial Industrial Quarter.
HBMS contacted Lehigh University’s Seismology class and Hoskins, a professor and postdoctoral researcher in the Earth and Environmental Sciences Department, to help discover remains of the old tawry, oil mill and butchery in the Colonial Industrial Quarter along the Monocacy Creek.
Relative locations of the torn down buildings are known due to exceptional record keeping. The purpose of uncovering the foundations of these buildings is to further understand and educate the public on the life of the 18th century Moravians.
The quarter can be considered America’s earliest industrial park with 35 crafts, trades and industries operating there in 1747. In the 1950s, the area unfortunately became home to a junk yard. Over the years, HBMS has transformed the site into a place to share the stories of early industry in Bethlehem.
Dr. Hoskins and eight of her students visited a cordoned-off area inside the Colonial Industrial Quarter and used a GPR device to look beneath the surface. The class did an analysis of the area between the gravel path south of the springhouse and the large tree just north of the Waterworks.
“The GPR survey we completed in the Colonial Industrial Quarter is similar to a CAT scan of the ground. Through GPR, we can, without disturbing the ground at all, find evidence of the walls of buildings and other disturbances beneath the ground and map their locations,” said Hoskins.
By pulsating electromagnetic waves into the ground, a high-resolution image of the subsurface was made and analyzed. In a summary written by the seismology students, it was indicated that the GPR image was able to capture differences in subsurface materials based on their differing electromagnetic properties.
By analyzing the different reflections of the electromagnetic waves, the exact location of the tawry foundation was found. The tawry was a key industry in 1700s Bethlehem because it supplied soft leather for book bindings, gloves, pocketbooks and knee breeches.
The Lehigh survey also located one of the foundation walls for the 1768 structure. The entire foundation was not discovered during the survey. The report indicated more time and data collection is necessary in order to locate the other walls.
“It is a great opportunity for us to work with Historic Bethlehem. The collaboration is a chance for the students to put what they are learning in the classroom into practice and, even better, to contribute to their community,” said Hoskins.